U.S. patent application number 12/749731 was filed with the patent office on 2010-10-21 for metering device.
This patent application is currently assigned to EPPENDORF AG. Invention is credited to Burkhardt REICHMUTH.
Application Number | 20100266454 12/749731 |
Document ID | / |
Family ID | 42229251 |
Filed Date | 2010-10-21 |
United States Patent
Application |
20100266454 |
Kind Code |
A1 |
REICHMUTH; Burkhardt |
October 21, 2010 |
Metering Device
Abstract
A metering device for utilisation with a syringe, which features
on a syringe cylinder a fastening portion with at least one axially
directed sensing surface projecting from the upside, and at least
one alignment nose projecting from the outer perimeter of the
fastening portion, and a plunger with a plunger rod, the metering
device having an accommodation for the fastening portion of the
syringe cylinder, the accommodation having an axial opening for
axially inserting the fastening portion into a fastening position,
a sensing device disposed in the accommodation with at least one
sensing means projecting from a basis surface of the sensing device
facing the axial opening, for sensing the at least one sensing
surface of a fastening portion inserted in a fastening
position.
Inventors: |
REICHMUTH; Burkhardt;
(Hamburg, DE) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
SUITE 400, 6640 SHADY OAK ROAD
EDEN PRAIRIE
MN
55344
US
|
Assignee: |
EPPENDORF AG
Hamburg
DE
|
Family ID: |
42229251 |
Appl. No.: |
12/749731 |
Filed: |
March 30, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61171208 |
Apr 21, 2009 |
|
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|
Current U.S.
Class: |
422/501 ;
422/509; 73/864.16 |
Current CPC
Class: |
B01L 2200/023 20130101;
B01L 3/0275 20130101; G01N 35/1016 20130101; B01L 3/0227 20130101;
B01L 3/0279 20130101; G01F 11/029 20130101; G01N 2035/1062
20130101; B01L 3/0217 20130101; B01L 2200/025 20130101 |
Class at
Publication: |
422/100 ;
73/864.16 |
International
Class: |
B01L 3/02 20060101
B01L003/02; G01N 1/14 20060101 G01N001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2009 |
DE |
10 2009 06 590.8 |
Claims
1. A metering device for utilisation with a syringe (19), which
features on a syringe cylinder (20) a fastening portion (21) with
at least one axially directed sensing surface (23) projecting from
the upside, and at least one alignment nose projecting from the
outer perimeter of the fastening portion (21), and a plunger with a
plunger rod, the metering device having an accommodation (3) for
the fastening portion (21) of the syringe cylinder (20), the
accommodation (3) having an axial opening (4) for axially inserting
the fastening portion (21) into a fastening position, a sensing
device (6) disposed in the accommodation (3) with at least one
sensing member (37) projecting from a basis surface (52) of the
sensing device (6) facing the axial opening (4), for sensing the at
least one sensing surface (23) of a fastening portion (21) inserted
in a fastening position, at least one axial guiding member (7) for
adjusting the at least one alignment nose (26) into an angular
position with respect to rotation around the axis of the metering
device, in which the syringe (19) is axially directed towards at
least one sensing member (26) with at least one sensing surface
(23), an accommodation body (8) with a plunger accommodation and a
further axial opening for axially inserting the plunger rod (31)
into a fastening position, fastening devices (13, 14) for
detachably holding fastening portion (21) and plunger rod (31) in
their fastening positions in the accommodations (3) and in the
plunger accommodation, and plunger adjustment devices (10) for
shifting the accommodation body (8), characterised in that the
axial guiding member (7) is present in the accommodation below the
sensing device (6), wherein the guiding member (7) has a guiding
contour (44) on the side that faces the axial opening (4), said
guiding contour (44) has at least one indentation (45) for
receiving at least one alignment nose (26) when the syringe (19) is
disposed with fastening portion (21) and plunger rod (31) being in
their fastening positions, and the at least one raised part (46)
neighbouring the indentation (45) has a distance from the basis
surface (52) of the sensing device (6) greater about .DELTA.h than
the at least one indentation (45), wherein the syringe (3) is
adapted to be displaced with the at least one alignment nose (26)
from out the at least one indentation (45) to the at least one
raised part (46).
2. A metering device according to claim 1, wherein the at least one
axial guiding member (7) has a guiding bridge and/or a guiding
groove in the axial direction.
3. A metering device according to claim 1, wherein plural sensing
members (37) are distributed over the perimeter of the sensing
device (6).
4. A metering device according to claim 1, wherein the sensing
device (6) is supported in the accommodation by way of at least one
spring member (41) acting axially against the displacement
direction of the fastening portion (21).
5. A metering device according to claim 4, wherein the guiding
member (7) is connected to the sensing device (6) and is supported
in the accommodation (3) by way of the at least one spring member
(41).
6. A metering device according to claim 1, wherein the fastening
members (13, 14) have radially feedable gripping equipments for
fixing the fastening portion (21) and the plunger rod (21) in the
fastening positions.
7. A metering device according to claim 1, wherein the guiding
member (7) is annular and has a guiding contour (44) with several
indentations (45) distributed over the perimeter and raised parts
(46) disposed between them.
8. A metering device according to claim 1, wherein the number of
the indentations (45) corresponds to the number of the sensing
member (37).
9. A metering device according to one of claims 7 or 8, wherein the
guiding contour (44) of the guiding member (7) gradually ascends
between the indentations (45) and the raised parts (46).
10. A metering device according to claim 9, wherein the transitions
between the indentations (45) and the raised parts (46) are
ramp-shaped and/or rounded.
11. A metering device according to claim 1, wherein all the
indentations (45) feature the same level with respect to the
sensing device (6), and/or wherein all the raised parts (46)
feature the same level with respect to the sensing device (6).
12. A metering device according to claim 1, with an analysing unit
(16) and/or display unit (17) connected to the sensing device
(6).
13. A metering device according to claim 1, wherein the plunger
adjustment devices (10) are manually and/or motor driven.
14. A metering device according to claim 1, which can be held by
the hand when metering.
15. A metering device according to claim 1, which is a stationary
metering device.
16. A metering device according to claim 1, characterised in that
the fastening portion of the syringe cylinder of the syringe (19)
is annular.
17. A metering device according to claim 1, characterised in that
the metering device is a pipette or a dispenser.
18. A metering device according to claim 1, characterised in that
the sensing device (6) is annular.
19. A metering device according to claim 1, characterised in that
the sensing surface (23) of the syringe features a flat surface
vertical to the axis of the pipette, which has local indentations
(50) with respect to this surface towards the downside, wherein a
sensing member (37) of the metering device is actuated by the
sensing surface (23) of the syringe opposite to it only then when
the sensing surface does not have any local indentations (24) there
and the at least one alignment nose (26) of the syringe is received
in an indentation (45) of the guiding member (7).
20. A metering device according to claim 1, characterised in that
the sensing surface (23) of the syringe features a flat surface
vertical to the axis of the pipette, which has local raised parts
raised against this surface towards the upside, wherein a sensing
member (37) of the metering device opposite to the sensing surface
is actuated by the sensing surface (23) of the syringe only then
when the sensing surface has a local raised part there and the at
least one alignment nose (26) of the syringe is accommodated in an
indentation (45) of the guiding member (7).
21. A metering device according to claim 7, characterised in that
the annular guiding member (7) has an outer ring with an inside
diameter R.sub.1, on which is disposed solely the guiding contour
(44) with the indentations (45) and raised parts (46).
22. A metering device according to claim 21, characterised in that
the sensing surface (23) of the syringe and the at least one
sensing member (37) are disposed within the outer ring.
23. A metering device according to claim 22, characterised in that
the sensing surface (23) of the syringe and the at least one
sensing member (37) are disposed exclusively within the outer
ring.
24. A metering device according to claim 7, characterised in that
annular guiding members (7) have abutment elements (51) in
addition, which bear two-dimensionally against a basis surface (52)
of the sensing device (53).
25. A metering device according to claim 24, characterised in that
the abutment elements (51) of the guiding member (7) are located
within the outer ring having an inside diameter R.sub.1.
26. A metering device according to claim 1, characterised in that a
syringe (19) is received by the fastening devices (13, 14) only
then when at least one alignment nose (46) of the syringe (19) is
received in the at least one indentation (45) of the guiding member
(7).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to provisional U.S. patent
Application No. 61/171,208, entitled Metering Device filed Apr. 21,
2009, the entire contents of which is incorporated herein by
reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention is related to a metering device for
utilisation with a syringe.
[0004] Metering devices serve for metering liquids and are used in
biological, chemical and medical laboratories in particular. In the
realisation as dispensers, they permit the stepwise delivery of a
liquid from a syringe. The metering amount per delivery step can be
adjustable in this. A dispenser with metering amount adjustment is
known from DE 29 26 691 C2, the entire contents of which is
incorporated herein by reference.
[0005] Furthermore, pipettes are known as metering devices, by
which an amount of liquid defined or adjustable via the apparatus
can be picked up and delivered again in one procedure.
[0006] Syringes of different sizes are frequently provided for
metering devices. These have in most cases different sizes of the
cross section. In the transition to another syringe size, the once
set metering amount does no more coincide with the real metering
amount. Metering devices have therefore become known wherein the
syringe has a code which is read by a sensing device of the
pipette. An analysing unit can determine the utilised syringe size
and indicate the metering amount that is effectively set.
[0007] A pipette system of the mentioned kind is known from EP 0
657 216 A2, the entire contents of which is incorporated herein by
reference, and from U.S. Pat. No. 5,620,661 A, the entire contents
of which is incorporated herein by reference. In this pipette
system, the pipette has an accommodation for a fastening portion of
a syringe in a pipette casing, and in an accommodation body it has
a plunger accommodation for the syringe plunger of the syringe.
Moreover, there are fastening devices for reversibly fixing
fastening portion and syringe plunger in their accommodations, and
plunger adjustment devices for displacing the accommodation body in
the pipette casing. The syringe features an information carrier
with information concerning the syringe and/or its condition, and
the pipette has a sensing device for the information on the
information carrier. Through axial openings in their
accommodations, the fastening portion and the syringe plunger are
axially shiftable into the pipette to their fastening positions,
the information carrier arriving in a sensing position with respect
to the sensing device through this. The syringe flange has an
annular collar with at least one axially directed sensing surface
with an axial position as information carrier, the syringe being
insertable into the pipette in different rotational positions. The
sensing device is made annularly with sensors distributed over the
perimeter. The sensors have elastic, compressible knobs projecting
from a front side of the sensing device that faces the axial
openings. Preferably, there is an analysing unit for the
information read by the sensing device and a display unit for the
set metering amount. There are alignment noses on the fastening
portion of the syringe and guiding grooves in the accommodation for
the fastening portion for reproducible alignment of the syringe
with its information carrier towards the sensing device. In a
practical embodiment, the syringe has plural alignment noses
uniformly distributed over the perimeter of the fastening portion,
which are guided on axially directed bridges on a lateral border of
the accommodation in order to direct the sensing surfaces towards
the sensors. The alignment noses are each one chamfered at both
sides on the upside, in order to guide the bridges into the grooves
between the alignment noses in case that the same are not exactly
directed towards the bridges.
[0008] The pipette system allows a user to utilise the syringe type
according to the practical needs and to adjust the metering amount
without sumptuous conversion work. The information may also concern
other specific data of the syringe and/or of the condition of the
syringe, for instance the purity condition or a filling material of
the syringe, which are automatically taken into account by the
pipette.
[0009] In spite of the essentially rotation-blocked mounting of the
syringe in the accommodation by guiding the alignment noses in the
guiding groove or on the axially directed bridges, respectively,
the syringes can be rotated in the accommodation when an increased
force is applied. This is due to the fact that the syringes are
made of a plastic material like polypropylene, so that the
alignment noses are deformed under load and may be pushed out of
the guiding grooves or over the bridges, respectively. The sensing
surfaces may laterally hit the projecting knobs of the sensing
device when the syringe is rotated, and shear the same off with the
electric contacts of the sensors, so that the metering device
becomes unusable. The danger of destruction of the metering device
is particularly high when a high-volume syringe is rotated in the
accommodation which has an adapter with a fastening portion that is
detachably connected to a syringe cylinder. Because this syringe
has a relatively great diameter, relatively high torques can be
introduced into the fastening of the syringe. The repair is
sumptuous and comprises the exchange of the relatively expensive
sensing device.
[0010] Starting from this, the present invention is based on the
objective to provide a metering device that is protected against
damage by distortion of a syringe.
BRIEF SUMMARY OF THE INVENTION
[0011] The metering device of the present invention for use with a
syringe, which features on a syringe cylinder a fastening portion
with at least one axially directed sensing surface projecting from
the upper side and at least one alignment nose projecting from the
outer perimeter of the fastening portion, and a plunger with a
plunger rod, said metering device has an accommodation for the
fastening portion of the syringe cylinder, with an axial opening
for axially inserting the fastening portion into a fastening
position, a sensing device disposed in the accommodation with at
least one sensing means projecting from a basis surface of the
sensing device facing the axial opening, for sensing the at least
one sensing surface of a fastening portion inserted in a fastening
position, at least one axial guiding means for adjusting the at
least one alignment nose into an angular position with respect to
rotation around the axis of the metering device, in which the
syringe is axially directed towards at least one sensing means with
at least one sensing surface, an accommodation body with a plunger
accommodation and a further axial opening for axially inserting the
plunger rod into a fastening position, fastening devices for
detachably holding fastening portion and plunger rod in their
fastening positions in the accommodations and in the plunger
accommodation, and plunger adjustment devices for shifting the
accommodation body, characterised in that the axial guiding mean is
present in the accommodation below the sensing device, wherein the
guiding means has a guiding contour on the side that faces the
axial opening, said guiding contour has at least one indentation
for receiving at least one alignment nose when the syringe is
disposed with fastening portion and plunger rod being in their
fastening positions, and the at least one raised part neighbouring
the indentation has a distance from the basis surface of the
sensing device greater about .quadrature.h than the at least one
indentation, wherein the syringe is adapted to be displaced with
the at least one alignment nose to the at least one raised part
from out the at least one indentation.
[0012] In the metering device of the present invention, by rotation
around the symmetry axis of the cylinder-plunger system of the
syringe which is inserted into the metering device, i.e. around the
axis of the metering device, a syringe when being inserted is
aligned by the co-operation of the alignment nose with the axial
guiding means into an angular position in which each sensing
surface of the syringe provided for this is axially directed
towards a sensing means. In this, with its fastening portion formed
on the cylinder and preferably being annular-shaped and located
preferably at the upper end of the cylinder, and also with its
plunger rod, the syringe arrives in the fastening position in which
it is detachably held by way of the fastening device. The pipette
can sense the sensing surfaces with its sensing device and acquire
the information about the syringe and/or its condition that is
contained in the number and/or the arrangement and/or the axial
position of the sensing surfaces. This information may be processed
and/or displayed via mechanical and/or electric and/or optical
analysing units and/or via display units. Applying a great force it
is possible to turn a syringe made of polypropylene or another soft
elastic plastic material away from this fastening position without
releasing the fastening means before, wherein each alignment nose
is pressed along an associated guiding means under deformation.
However, the present invention prevents that a damage of the
preferably annular sensing device is accompanied by this. This is
achieved by the preferably annular guiding means, which receives
the at least one alignment nose in at least one indentation,
provided that the syringe is correctly directed towards a sensing
means with every sensing surface that is provided for this. When
twisting the syringe, the at least one sensing surface slides from
out the at least one indentation to the at least one raised surface
which has a greater distance from the sensing device, so that the
syringe cylinder is displaced away from the sensing device. In
this, the sensing surfaces are displaced away from the annular
sensing device, so that they do not damage the sensing means
projecting from there and the sensing means are actuated no more.
In the twisting, the fastening portion is preferably moved away
from the annular sensing device so far that the sensing surfaces
just no more touch the sensing means. Thus, the present invention
takes the finding into account that a forced twisting of the
syringe out of its fastening position in the metering device cannot
be prevented due to the soft elastic plastic materials that are
used for the syringe. However, the metering device of the present
invention prevents damage of the expensive sensing device by having
means which transform a rotation of the syringe with respect to the
pipette into a shifting apart of fastening portion and sensing
device.
[0013] According to one embodiment, the at least one axial guiding
means has a guiding bridge and/or a guiding groove in the axial
direction. Also, parallel axial guiding bridges can limit a guiding
groove.
[0014] The information regarding the syringe and/or its condition
may be contained in the number and/or arrangement and/or the axial
position of one or plural sensing surfaces on the fastening portion
of the syringe. Preferably, the sensing surfaces that characterise
the syringe are all disposed in one single defined distance from
the upside of the fastening portion, so that a binary
representation of the information which excludes sensing errors as
far as possible can be achieved by disposing or omitting sensing
surfaces at a certain perimeter position of the fastening
surface.
[0015] The present invention incorporates embodiments in which the
annular sensing device has only one single sensing means. According
to a preferred embodiment, plural sensing means are distributed
over the perimeter of the sensing device. Through this, information
can be read from a syringe having plural sensing surfaces that are
distributed on the perimeter.
[0016] In a further embodiment, the metering devices of the present
invention can also receive syringes which have a flat surface
vertical to the axis of the syringe and so also to that of the
metering device as a sensing surface, wherein this surface has
local indentations which characterise the respective syringe type.
The sensing means provided in the sensing device have to be
positioned exactly opposite to these indentations in order to read
this code. This is achieved by the guiding means when the at least
one alignment nose of the syringe is received in the indentation of
a guiding means. Now, the sensing means are designed such and the
guiding means is dimensioned such that the sensing means are
actuated only when the alignment noses sit in the indentations of
the guiding means and the sensing surface facing the sensing means
has no local indentation. Thus, the sensing means are released only
there where the flat sensing surface is facing them. However, this
code can be perceived by the sensing means only when the sensing
surface is sufficiently approached by the sensing means through the
insertion of the alignment noses into the guiding means of the
sensing device. When the alignment noses of the syringe are not
already in the indentation, any contact of the sensing means by the
syringe is excluded. The sensing means can then not be actuated
neither be damaged by a rotational movement of the syringe.
[0017] In another embodiment, the metering devices of the present
invention can also receive syringes which have a flat surface
vertical to the axis of the syringe and thus also to that of the
metering device as a sensing surface, wherein this surface has
local raised parts which characterise the respective syringe type.
The sensing means provided in the sensing device have to be
positioned exactly opposite to these raised parts in order to read
this code. This is achieved by the guiding means when the at least
one alignment nose of the syringe is received in the indentation of
a guiding means. Now, the sensing means are designed such and the
guiding means are dimensioned such that the sensing means are
actuated only when the alignment noses sit in the indentations of
the guiding means and the sensing surface facing the sensing means
has a local raised part. Thus, the sensing means are released only
there where a raised part of the otherwise flat sensing surface is
facing them. However, this code can be perceived by the sensing
means only when the sensing surface is sufficiently approached by
the sensing means through the insertion of the alignment noses into
the guiding means of the sensing device. When the alignment noses
of the syringe are not already in the indentation, any contact of
the sensing means by the syringe is excluded. The sensing means can
then not be actuated neither be damaged by a rotational movement of
the syringe.
[0018] In principle, the preferably annular sensing device may be
disposed rigidly with respect to the accommodation. In a preferred
embodiment, it is supported in the accommodation by way of at least
one spring means acting axially against the displacement direction
of the fastening portion. The spring means catches when the pipette
is inserted. Through this, tolerances are compensated and damage of
the sensing device is avoided.
[0019] Springy holding means can exist for the fastening portion,
so that fastening portion and sensing device can be displaced away
from each other when the syringe is rotated. For instance, the
fastening devices can be realised in a springy fashion. Further, it
is possible to make the fastening portion springy on locations that
are held by the fastening devices. According to a preferred
embodiment, the preferably annular guiding means is connected to
the sensing device and is supported in the accommodation by way of
the at least one spring means. In this embodiment, twisting of the
syringe that is detachably held in the pipette results in a
movement of the annular guiding means, accompanied by taking along
the preferably annular sensing device, wherein the at least one
spring means catches in. As a result, the sensing device evades
from the sensing surfaces of the syringe and will not be
damaged.
[0020] The springy realisation of sensing devices, and as the case
may be of guiding means, facilitates the automatic separation of
pipette and syringe after releasing the fastening means.
[0021] The fastening means can be realised differently. According
to a preferred embodiment, the fastening means are radially
feedable gripping equipments for fixing the fastening portion and
the plunger rod in the fastening positions.
[0022] The present invention incorporates embodiments with only one
indentation of the annular guiding means. According to a preferred
embodiment, the annular guiding means has a guiding contour with
several indentations distributed over the perimeter, and raised
parts disposed between them. The insertion of the syringe into the
pipette is facilitated through this. Preferably, the number of the
indentations corresponds to the number of the sensing devices.
Moreover, when the number of the sensing surfaces corresponds to
the number of the sensing means, it is made sure that all the
sensing surfaces are sensed by sensing means in every setting
position of the syringe.
[0023] Gradual removal of the fastening portion from the sensing
device when the syringe is rotated in the pipette can be made sure
by a suitable contour of the alignment nose in particular. For this
purpose, the alignment nose may be rounded or chamfered on both
side at the upside. According to a preferred embodiment, the
guiding contour gradually ascends between the indentations and the
raised parts. This favours a smooth gliding of the alignment noses
over the guiding contour in the rotation of the syringe, in
particular in co-operation with rounded or chamfered sides of the
at least one alignment nose. According to a further embodiment, the
transitions between the indentations and the raised parts are
ramp-shaped and/or rounded.
[0024] According to a preferred embodiment, all the indentations
are on the same level with respect to the annular sensing device,
and/or all the raised parts are on the same level with respect to
the sensing device.
[0025] According to a further embodiment, the plunger adjustment
devices are manually and/or motor driven. A manual plunger
adjustment device is described in DE 29 26 691 C2, the entire
contents of which is incorporated herein by reference, and in U.S.
Pat. No. 4,406,170 A, the entire contents of which is incorporated
herein by reference. The explanations relating to this are
incorporated into the present application by reference.
[0026] According to a further embodiment, the metering device has
an analysing unit and/or a display unit connected to the sensing
device for the information read by the sensing device. The
analysing unit can process the read-out information taking into
account a metering amount setting of a plunger adjustment device in
particular, and display the respective metering amount or the
respective dispensing volume, respectively, on the display
unit.
[0027] In principle, the metering device can be realised on a frame
or another supporting structure. According to a preferred
embodiment, the metering device has a casing which comprises the
following components completely or partly: the accommodation, the
sensing device, the axial guiding means, the accommodation body,
the fastening means, the plunger adjustment devices, the guiding
means, the analysing unit and the display unit.
[0028] According to one embodiment, the metering device is
constructed such that it can be held by the hand when metering.
According to a further embodiment, the metering device is a
stationary metering device. It is also possible to design the
metering device such that it can be selectively either held by hand
or be operated as a stationary device. Further, the metering device
can be made to be adapted for actuation by hand and/or
automatically, that is to say, the metering processes can be
controlled by hand and/or automatically. The metering device of the
present invention may be a dispenser as well as a pipette.
[0029] The metering device of the present invention may be utilised
with syringes whose syringe cylinder is connected in one piece with
a fastening portion. It is also related to syringes where the
fastening portion is formed on an adapter which is detachably
connected to the syringe cylinder, for instance via a bayonet
joint, a screw joint or a clamping joint. Adapters are used with
high-volume syringes in particular. These may be syringes with a
capacity of 25 ml or 50 ml in particular.
[0030] The metering device can have further features of the pipette
system according to EP 0 657 216 A, the entire contents of which is
incorporated herein by reference, for U.S. Pat. No. 5,620,661 A,
the entire contents of which is incorporated herein by reference.
This holds in particular for the design of the accommodation, of
the sensing device, the axial guiding means, the accommodation body
and the fastening means according to the aforementioned documents.
In particular, the metering device may co-operate with syringes
which are described in the aforementioned documents. The
specifications concerning this in EP 0 657 216 A2 and U.S. Pat. No.
5,620,661 A are incorporated into the present application by
reference.
[0031] In a preferred embodiment of the present invention, the
guiding means of the metering device is annular and has an outer
ring with an inside diameter D.sub.1. On the side of this ring that
faces the axial opening of the metering device, the guiding contour
of the guiding means with its indentations and raised parts is
situated. The sensing surface of the syringe and the sensing means
of the sensing device are disposed within the outer ring of the
guiding means.
[0032] The guiding means of the metering device of the present
invention has preferably also abutment elements, which bear
two-dimensionally against a basis surface of the sensing device.
The basis surface is distinguished in that the sensing means of the
sensing device are radially projecting from it. In this, the basis
surface is preferably flat and particularly preferably it stands
vertical to the symmetry axis of the cylinder-plunger system of the
metering device. The guiding means are preferably annularly shaped
in this. In a guiding means with an outer ring on which the guiding
contour of the guiding means is situated, the abutment elements are
preferably disposed within the outer ring having an inside radius
D.sub.1.
[0033] The metering device of the present invention is preferably
constructed such that its fastening means can receive a syringe
only then when the at least one alignment nose of the syringe is
received in the at least one indentation of the guiding means. In
order that a syringe is received by the fastening means, it has to
be put into the syringe in particular such that the at least one
spring means supporting the sensing device is compressed.
Preferably, the guiding contour of the guiding means of the
metering device is shaped such that the at least one alignment nose
of the syringe is unavoidably moved into the associated indentation
of the guiding means.
[0034] A metering device for utilisation with a syringe, which
features on a syringe cylinder a fastening portion with at least
one axially directed sensing surface projecting from the upside,
and at least one alignment nose projecting from the outer perimeter
of the fastening portion, and a plunger with a plunger rod, the
metering device having an accommodation for the fastening portion
of the syringe cylinder, the accommodation having an axial opening
for axially inserting the fastening portion into a fastening
position, a sensing device disposed in the accommodation with at
least one sensing means projecting from a basis surface of the
sensing device facing the axial opening, for sensing the at least
one sensing surface of a fastening portion inserted in a fastening
position, at least one axial guiding means for adjusting the at
least one alignment nose into an angular position with respect to
rotation around the axis of the metering device, in which the
syringe is axially directed towards at least one sensing means with
at least one sensing surface, an accommodation body with a plunger
accommodation and a further axial opening for axially inserting the
plunger rod into a fastening position, fastening devices for
detachably holding fastening portion and plunger rod in their
fastening positions in the accommodations and in the plunger
accommodation, and plunger adjustment devices for shifting the
accommodation body, wherein the axial guiding mean is present in
the accommodation below the sensing device, wherein the guiding
means has a guiding contour on the side that faces the axial
opening, said guiding contour has at least one indentation for
receiving at least one alignment nose when the syringe is disposed
with fastening portion and plunger rod being in their fastening
positions, and the at least one raised part neighbouring the
indentation has a distance from the basis surface of the sensing
device greater about .DELTA.h than the at least one indentation,
wherein the syringe is adapted to be displaced with the at least
one alignment nose from out the at least one indentation to the at
least one raised part.
BRIEF DESCRIPTION OF EACH OF THE FIGURES OF THE DRAWINGS
[0035] The present invention will be explained in more detail below
by way of the attached drawings, which show a preferred embodiment
of an annular sensing device, an annular guiding means and an
adapter. In the drawings show:
[0036] FIG. 1 a schematic view of the essential elements of a
metering device according to the state of the art, with syringe
separated from it, in a longitudinal section,
[0037] FIG. 2 an adapter in an enlarged perspective view, slantly
from the upside and from the side,
[0038] FIG. 3 the syringe in a side view,
[0039] FIG. 4 detailed view of the fastening portion of the syringe
according to FIG. 3,
[0040] FIG. 5 arrangement with an annular sensing device and an
annular guiding means on a mounting plate in a perspective view,
slantly from the upside and from the side,
[0041] FIG. 6 an exploded view of the individual components of the
arrangement according to FIG. 5,
[0042] FIG. 7 a detail view of a region shown in FIG. 5, in
particular of the guiding means of the metering device,
[0043] FIG. 8 an adapter in the correct fastening position, held by
gripping equipments in the arrangement of FIG. 3, in a side
view,
[0044] FIG. 9 the fastening portion of the adapter in the same
position on the annular sensing device, omitting the annular
guiding means and the gripping equipments, in an enlarged
perspective partial view,
[0045] FIG. 10 an adapter in an arrangement of FIG. 3, held in a
twisted position by way of gripping equipments, in a side view,
[0046] FIG. 11 the fastening portion of the adapter in the same
position on the annular sensing device, omitting the annular
guiding means and the gripping equipments, in an enlarged
perspective partial view.
DETAILED DESCRIPTION OF THE INVENTION
[0047] While this invention may be embodied in many different
forms, there are described in detail herein a specific preferred
embodiment of the invention. This description is an exemplification
of the principles of the invention and is not intended to limit the
invention to the particular embodiment illustrated
[0048] In the present application, the indications "up" and "down",
as well as "upside" and "downside" refer to the preferred alignment
of the metering device in the operation, wherein the metering
device is aligned vertically and a syringe connected to the
metering device is disposed below the metering device.
[0049] According to FIG. 1, a metering device 1 of the state of the
art actuated by hand comprises a casing 2, which has an
accommodation 3 at the downside, which is accessible from the
outside through an axial opening 4 on the lower end.
[0050] The accommodation 3 has an approximately circular cross
section.
[0051] An annular sensing device 6 is disposed on the bottom 5 of
the accommodation 3.
[0052] On the side walls that laterally limit the accommodation 3,
there are lateral guiding means 60 in the form of axially running
ribs. In the example, three ribs are distributed over the perimeter
of the accommodation 3.
[0053] Above the accommodation 3, an accommodation body 8 exists in
the casing 2 of the metering device. The same is connected at its
upper end with a driving rod 9 of plunger adjustment devices 10 for
axially displacing the accommodation body 8 in the pipette casing
2. The plunger adjustment devices 10 feature a draw-up lever 11 for
drawing up liquid for a syringe that is to be connected to the
pipette 1. Further, they have a metering lever 12 for delivering
liquid from a syringe.
[0054] Fastening devices 13 in the form of radially feedable
gripping equipments for a syringe cylinder 13 and for a syringe
plunger 14 (not shown) are associated to the accommodation 3 and
the accommodation body 8. The fastening devices 13, 14 are realised
as pivotally mounted gripping levers, which co-operate when a
syringe is detached from the metering device 1.
[0055] On the upside of the casing of the metering device 2, there
is an adjustment device 15 for am metering step width in the form
of a little adjustment wheel, which is connected to the plunger
adjustment devices 10. Furthermore, at the upside in the casing of
the metering device 2 there is an analysing unit 16, which is
connected to the sensing device 6 and the adjustment device 15, in
order to determine the respective metering or dispensing volume,
respectively, by way of the code of an inserted syringe detected by
the sensing device 6 and the metering step width given by the
adjustment device 15. The analysing unit 16 is connected to a
display unit 17 in the form of a LCD display, disposed at the
upside on the pipette casing 2, which displays the respective
dispensing volume that is set. Further, the casing of the metering
device 2 contains a power supply in the form of a battery or an
accumulator.
[0056] An example for a pipette 1 with the features described above
is described in EP 0 657 216 A2, the entire contents of which is
incorporated herein by reference, and in U.S. Pat. No. 5,629,661 A,
the entire contents of which is incorporated herein by reference.
The specifications concerning this in the description of the
figures of the above-mentioned documents are incorporated into the
present application.
[0057] Besides, the metering device 1 of the present invention has
an annular guiding means 7 at the bottom 5 of the accommodation 3
that concentrically surrounds the annular sensing device 6 and
whose details and function will be described by way of the FIGS. 5
to 11.
[0058] A syringe 19 to be connected to the metering device 1 has a
syringe cylinder 20, shown enlarged in FIG. 3, with an annular
fastening portion 21 in the form of a flange. The fastening portion
21 is dimensioned such that it fits into the accommodation 3
through the axial opening 4. At an upside of the fastening portion
21, there are axially projecting sensing surfaces 23. The sensing
surfaces 23 have indentations 24, 24 on the upside 22. Number and
arrangement of the indentations 24 encode a syringe 19 that has a
certain volume. This is shown in detail in FIG. 4.
[0059] Several alignment noses 26 are present on the perimeter 25
of the fasting portion 21. The alignment noses 26 are uniformly
distributed over the perimeter 25. They are formed by projections
on the perimeter 25. The two side surfaces 27, 28 of every
alignment nose 26 converge towards the upside. In the example, they
are rounded. Between neighbouring alignment noses 26, there is a
gap 29, which can receive an axial guiding means 7.
[0060] A plunger is disposed in the syringe cylinder 20, which is
connected in one piece with a plunger rod 31 that projects out of
the syringe cylinder 20.
[0061] Further, big syringes can be connected to the metering
device 1, whose syringe cylinder has a cross section which exceeds
that of the accommodation 3. These syringe cylinders are connected
at the upside via a clamping-, bayonet or screw joint to an adapter
32, which is also shown in FIG. 2.
[0062] The adapter 32 has a cap-like connecting portion 33, which
bears a tube piece 34 on the upside, which corresponds to the upper
end region of a syringe cylinder 20. The tube piece 34 has an
annular fastening portion 21.1 with a sensing surface 23.1, which
has indentations 24.1 to 24.4 which encode the big syringe received
by the adapter. Further, alignment noses 26.1 with gaps 29.1
between them exist on the perimeter of the fastening portion 21.1.
The adapter 32 is can be inserted into the accommodation 3 with its
fastening portion 21.1.
[0063] Examples for syringes of the kind described above are
described in EP 0 657 216 A2 and U.S. Pat. No. 5,620,661 A. The
specifications concerning this in the above-mentioned documents are
incorporated into the present application by reference.
[0064] In FIGS. 5 and 6, an annular sensing device 6 and an
associated annular guiding means 7 are shown, which are disposed on
a mounting plate 60 that is positioned in the accommodation 3 of a
metering device of the present invention. Whereas FIG. 5 shows this
assembly group like as it is disposed in the metering device, the
elements of the assembly group are shown individually in the
exploded view of FIG. 6, for the sake of better illustration.
According to FIGS. 5 and 6, the annular sensing device 6 features
sensors 35 that are uniformly distributed over the perimeter. These
have sensing means 37 in the form of sensing buttons which project
from a basis surface 52 of the annular-disc shaped sensing device
6. The sensing means 37 are realised as knobs of an annular disc
made of silicone, which sit on an annular circuit board with strip
conductors on the side facing the annular disc. The knobs have a
cavity which is opened at the side towards the strip conductors. On
the bottom of the cavity, the knobs bear an electrically conductive
material in the form of a conduction pill or a conductive paint.
When a knob is axially compressed, the conductive material contacts
two strip conductors and connects them electrically. A circuit is
closed by this. After relief, the knob springs back elastically
into an unloaded starting position.
[0065] An embodiment of this sensing device 6 is described in EP 0
657 216 A2 and U.S. Pat. No. 5,620,661 A. Their specifications
concerning this are incorporated into the present application by
reference.
[0066] The mounting plate 60 has four bores on laterally projecting
edge regions 38, which are guided on stay bolts 39 which project
from a holder plate 40. Spring means 41 in the form of helical
springs are guided on the stay bolts 39 between the holder plate 40
and the mounting plate 60.
[0067] The sensing device 6 has a contact bank 42 on its edge,
which is connected to the sensors. The contact bank 42 is connected
to a flat cable 43, which is guided towards the analysing unit
16.
[0068] The annular guiding means 7 has a guiding contour 44 with
indentations 45 and raised parts 46, shown in detail in FIG. 7,
which shows the cut-out shown in a circle in FIG. 5 in an enlarged
view. The raised parts 46 each have the same angular position as do
the sensing means 37. The indentations 45 are at half angle between
two neighbouring sensing means at a time. Three raised parts 46 are
provided with recesses 47 on the upper edge, into which the upper
ends of the lateral guiding means 60 of the metering device can
engage.
[0069] The indentations 45 are rounded, so that they gradually
ascend up to the raised parts 46. The indentations 45 have a form
that is complementary to the upper sides of the alignment noses 26,
26.1. The raised parts 46 are flattened.
[0070] The indentations 45 all have the same level with respect to
the basis surface 52 of the sensing device 6. The raised parts 46
are more distant from the basis surfaces 52. They all have the same
distance from the basis surface 52. The difference .DELTA.h between
the distance of the raised part 46 from the basis surface and that
of the indentation 25 from the basis surface is preferably 0.5 to 2
mm, particularly preferably 1 to 1.5 mm.
[0071] The annular sensing means 7 is likewise guided on the stay
bolts 39 in bores in laterally projecting edge regions 48. At the
inside, the guiding means 7 has abutment elements 51 in the form of
console-shaped projections next to the indentations 45, which bear
against the basis surface 52 of the sensing device 6.
[0072] The guiding means 7 and the sensing device 6 are rigidly
connected to each other.
[0073] According to FIGS. 8 and 9 (guiding means 7 omitted for
better representation), the adapter 32 put into the accommodation 3
is fixed in the pipette 1 by way of the gripping equipments 13. The
lateral guiding means 60 engage into the recesses 47 between the
alignment noses 26.1. The alignment noses 26.1 are disposed in the
indentations of the annular guiding means 7. The spring means 42
are somewhat under spring tension.
[0074] The sensing surfaces 23 bear against the associated sensing
means 37 and press the same together, so that they contact each
other.
[0075] According to FIGS. 10 and 11 (sensing means 7 omitted for
better illustration), the adapter 32 is twisted in the
accommodation 3, so that the lateral guiding means 60 do no more
engage into the recesses 47. Moreover, the alignment noses 26.1 sit
on the raised parts 46 of the annular guiding means 7. Because the
adapter 32 is to be kept in the accommodation 3 by way of the
gripping equipments 13, the alignment noses 26.1 press the
arrangement consisting of the annular guiding means 18 and the
sensing device 6 upward, so that the spring means 41 continue to
catch. In order to escape the very big force that occurs in this,
the user of the metering device will rotate the syringe during the
insertion, due to the contour of the alignment noses 26, 26.1 and
the guiding means 7. When the adapter 32 is rotated in the
accommodation 3, the sensing device 6 is moved by the sensing
surfaces 23 of the adapter 32 in a distance, so that the sensing
surfaces 32 do not shear off the sensing means 37. By the rotation,
the alignment noses 26, 26.1 arrive then unavoidably in the
indentations 25 of the guiding means, so that the correct regions
of the sensing surface 23 are facing the sensing means 37 again, so
that the same can acquire the code of the syringes 19 or the
syringe adapters 19.1.
[0076] Thus, the sensing device 6 is not damaged at all. Only the
sensing is put out of function due to the twisting of the adapter
32 out of the correct position.
[0077] The above disclosure is intended to be illustrative and not
exhaustive. This description will suggest many variations and
alternatives to one of ordinary skill in this art. All these
alternatives and variations are intended to be included within the
scope of the claims where the term "comprising" means "including,
but not limited to". Those familiar with the art may recognize
other equivalents to the specific embodiments described herein
which equivalents are also intended to be encompassed by the
claims.
[0078] Further, the particular features presented in the dependent
claims can be combined with each other in other manners within the
scope of the invention such that the invention should be recognized
as also specifically directed to other embodiments having any other
possible combination of the features of the dependent claims. For
instance, for purposes of claim publication, any dependent claim
which follows should be taken as alternatively written in a
multiple dependent form from all prior claims which possess all
antecedents referenced in such dependent claim if such multiple
dependent format is an accepted format within the jurisdiction
(e.g. each claim depending directly from claim 1 should be
alternatively taken as depending from all previous claims). In
jurisdictions where multiple dependent claim formats are
restricted, the following dependent claims should each be also
taken as alternatively written in each singly dependent claim
format which creates a dependency from a prior
antecedent-possessing claim other than the specific claim listed in
such dependent claim below.
[0079] This completes the description of the preferred and
alternate embodiments of the invention. Those skilled in the art
may recognize other equivalents to the specific embodiment
described herein which equivalents are intended to be encompassed
by the claims attached hereto.
* * * * *